Gas lock



E. G. VOGT Sept. 24, 1957 GAS LOCK Filed Aug. 26, 1955 INVENTOR.

l-DwMD a vow w/M, 52% M 1415 Arne/v5 Y5 United States Patent GAS LOCK Edward G. Vogt, Library, Pa., assignor to Universal- Cyclops Steel Corporation, Bridgeville, Pa, a corporation of Pennsylvania Application August 26, 1955, Serial No. 530,864

7 Claims. (Cl. 20-4) This invention relates to gas locks for access to chambers containing special atmospheres, and more particularly to such locks for accommodating men..

When a chamber, which a man must enter periodically, contains a special atmosphere, the problem arises as to how to prevent that atmosphere from escaping or being diluted by the outside air as the man enters or leaves the chamber. A number of solutions may come to mind at once, but it will be found that they require too much time for a man to enter or leave the chamber, and generally also require the use of pressure producing or reducing means.

It is among the objects of this invention to provide a gas lock for passage of a man, which does not require a man to wait in it, which is operated entirely by the man passing through it, which occupies but little space, which uses no pumps or other pressure changing apparatus, which has nothing to get out of order, and which is simple and inexpensive in construction.

In accordance with this invention, an airtight chamber, containing a special or controlled atmosphere, is provided in a side wall with a door frame that forms a doorway. The opposite sides of the doorway normally are closed by a pair of doors mounted for movement outwardly away from each other. The distance between the closed doors is more than great enough to accommodate a man, but a pair of soft resilient pads secured to the inner surfaces of the doors substantially fill all of the space between them. The pads are resilient enough to permit them to substantially engage each other around a man standing between the pads while the doors are closed, so that most of the gas, whether controlled atmosphere inside the chamber or outside air, will be excluded from the doorway.

The invention is illustrated in the accompanying drawings, in which Fig. l is an elevation of my gas lock, viewed from the outside of the chamber;

Fig. 2 is an enlarged horizontal section, taken on the line II-II of Fig. 1, indicating a man in the lock;

Fig. 3 is a central vertical section through a lock with modified pads; and

Fig. 4 is a horizontal section through a door using another form of pad.

Referring to Figs. 1 and 2 of the drawings, a wall 1 of a gas tight chamber, in which there is a controlled atmosphere (argon for example), is provided with an opening containing a heavy door frame 2. The thickness of the frame is considerably more than enough to permit a man M (Fig. 2) to stand completely within the doorway. The opposite sides of the doorway are normally closed by a pair of airtight doors 3 and 4. Each door overlaps the frame a short distance and carries sealing gasket 5 across the top and down the sides of the inner surface of the door. The bottom edge of the door can be provided with a sealing strip 6 engaging the floor. One edge of each door is hinged to the frame by hinges 7.

When the doors are closed the space between them is not empty, but, according to this invention, is substanice tially completely filled with two thick pads of resilient material. The pads preferably have the same thickness so that they will meet at the center of the doorway. The outer surface of each pad is cemented or otherwise secured to the adjoining door. The pads are soft and highly resilient so that they can be compressed a considerable amount and will conform snugly to the shape of any large object pressed against them. A suitable material is sponge rubber 9. 1

Because of the great depth of the doorway, it is desirable that the doors not swing on too short a radius when they are opened and closed, as the pads might interfere. Therefore, the hinges 7 preferably have long arms so that they can be pivoted near the outer edges of the door frame. Also, to permit the thick pads to swing into the doorway and fit snugly against its sides, the pads are tapered horizontally inward and the frame conforms to the taper. The doors are urged closed by means of springs 10, which may extend from the centers of the hinges to the sides of the frame.

When a man wishes to enter the controlled atmosphere room he mayput on self-contained breathing apparatus B and then open the outer door 3. He then steps into the doorway and against the pad on the inner door. The outer door is swung against him by means of springs 10, and the outer pad is compressed around him. He shuflles slowly forward, pressing farther into the inner pad to allow the outer door to close. By the time the outer door has closed, the man will be at about the center of the doorway with the two pads pressed tightly against him and more or less engaging each other around him as shown in Fig. 2. This means that substantially all of the space between the doors that is not taken up by the mans body and his breathing apparatus is filled with the pads, so most of the air in the doorway is excluded. The inner door then can be opened by the man pushing against it, and he steps into the chamber without any appreciable quantity of outside air entering with him and without any of the atmosphere of the chamber escaping.

To help prevent air or the chamber gas from being trapped in the doorway when either door closes, it is desirable to provide vents. One way of doing this is to form passages 12 and 13 in the door frame at the side opposite to the hinges. Outer passage 12 extends from an outlet 14 near the center of the doorway outward through the frame to the outside of the chamber, and inner passage 13 extends from outlet 15 near outlet 14 inward to the chamber side of the door frame. When the outer door 3 closes, air that might otherwise be trapped in the doorway can escape back to the atmosphere through vent passage 12. The inner pad may cover the outlet 15 well enough to prevent the air from being forced through passage 13. However, to be safe, the outer end of vent 13 may be located within the area of the inner door enclosed by gasket 5. The inner door then will serve as a Valve closing vent passage 13. The other vent 12 may be located in the same general position relative to the outer door, so that there will be no chance of gas from the chamber being forced out through that vent when the inner door is closed.

In the modification shown in Fig. 3, each sponge rubber cushion 17 is covered with a thin, resilient sheet 18 of rubber or the like to seal the pores of the sponge. This sheet also permits the inner surface of the cushion to be provided with a recess 19 so that the cushion will not have to be compressed so much when a man is between the pads. Instead, the flexible sheets will be pressed back into the cushion recesses, which will form a cavity that will take a large part of the mans body.

The resilient pad carried by the door 21'shown in Fig. 4 is formed from an inflated balloon-like pad 22 having the same shape as the pads in Fig. 2. Two of these ho1- low .pads will fit snugly around a man against which they are pressed from opposite sides.

With a lock constructed in accordance with this invention, there is no machinery to operate and maintain and nothing else toget outof'order. A man sim-ply walks through the lock, which is operated merely by the closing of the door behind 'him. Although he should proceed slowly, it is not necessary that he stop in the lock and wait for anything to happen.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now'consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Iclaiin:

1. A gas lock for .passage of a man into and out of a chamber containing a controlled atmosphere, comprising a door frame forming a dorwayi for the wall of the chamber, a pair of doors normally closing the opposite sides of the doorway and hinged for swinging outwardly away from each other, the distance between the closed doors being more than great enough for a man to stand between them and a pair of soft resilient pads secured to the inner surfaces of the doors and substantially filling all of. the space between them, said pads being resilient enough to permit them to substantially engage each other around a man standing between the pads while the doors are closed, whereby to exclude most of the gas from the doorway.

2. A gas lock according to claim 1, in which each of said pads is formed from a sponge rubber cushion covered with an impervious flexible sheet.

3. A gas lock according to claim 1, in which each of said pads is formed from a hollow airtight cushion.

4, A gas lock according to claim 1, in which each of said pads is formed from a sponge rubber cushion covered with an impervious flexible sheet and the inner surface of at least one of said cushions is provided with a recess to receive part of the body of the man.

5. A gas lock for passage of a man into and out of a chamber containing a controlled atmosphere, comprising a door frame forming a doorway for the wall of the chamber, a hinged door for each side of the doorway, means urging the doors toward each other for normally closing the doorway, the distance between the closed doors being more than great enough for a man to stand between them, and a pair of soft resilient pads secured to 4 theinher surfaces of the doors and substantially filling all of the space between them, said pads being resilient enough to permit them to substantially engage each other around a man standing between the pads while the doors are closed, said door closing means being strong enough to close the doors when there is a man between them.

6. A gas lock for passage of a man into and out of a chamber containing a controlled atmosphere, comprising a door frame forming" a doorway for the wall of the chamber, a pair of doors normally closing the opposite sides of the doorway, hinges at one side of each door to permit it to be swung away from the other door, said frame at the opposite side of each door being provided with a vent passage extending inwardly to a point near the center of the doorway, the distance between the closed doors being more than great enough for a man to stand between them, and a pair of soft resilient pads secured to the inner surfaces of the doors and substantially filling all of the space between them, saidpads being resilient enough to permit them to' substantially engage each other around a man standing between the pads while the doors are closed, whereby to exclude most of the gas from the doorway.

7. A gas lock for passage of a man into and out of a chamber containing a controlled atmosphere, comprising a door frame forming a doorway for the wall of the chamher, a pair of doo'rs normally closing the opposite sides of the doorway, hinges at one side of each door 'to permit it to be swung away from the other door, the opposite side of each door overlapping the door frame in sealing engagement therewith, said frame being provided with a vent passage extending from near the center of the doorway to a point covered by said frame-overlapping portion of the door, the distance between the closed doors being more than great enough for a man to stand between them, and a pair of soft resilient pads secured to the inner surfaces of the doors and substantially filling all of the space between thein, said pads being resilient enough to permit them to substantially engage each other around a man standing between the pads while the doors are closed,- whe'reby to exclude most of the gas from the doorway.

References Cited in the file of this patent UNITED STATES PATENTS 1,11o,410 Thayer, Jr Sept. 15, 1914 2,428,995 Rogers Oct. 14, 1947 2,487,226 Eastman Nov. 8, 1949 

